Stiff peaks

Stiff peaks is the stage where whipped egg whites or cream hold a sharp, upright point when you lift the whisk. The tip stays straight and does not curl over. The foam is firm, thick and, for egg whites with sugar, very glossy. You need stiff peaks for meringue, for whites folded into a soufflé, and for cream that has to hold its shape when piped.

How to do it

1. Start with a clean, dry, grease-free bowl. For cream, chill the bowl and use cold cream.
2. Whip on medium speed until you reach soft peaks.
3. For meringue, add sugar a spoonful at a time at this point.
4. Raise the speed to medium-high and keep whipping.
5. Stop every 20 to 30 seconds near the end and check the peak.

With a mixer, egg whites usually take 3 to 6 minutes in all, and cream 3 to 5 minutes. By hand it takes much longer.

How to tell it is done

• Lift the whisk and hold it upright. The peak stands straight up and keeps its point.
• Tip the bowl. The foam does not slide at all.
• Egg whites with sugar look smooth and shiny, like satin. Cream looks thick and holds clear ridges.

Why it works

The longer you whip, the more air goes in and the tighter the network around the bubbles becomes. In egg whites, proteins link into firm walls. In cream, fat droplets clump together around the bubbles. At stiff peaks the network is strong enough to hold its shape on its own.

Common mistakes

• Overwhipping egg whites without sugar. They turn dry, grainy and lumpy and start to leak liquid. They will not fold in smoothly.
• Overwhipping cream. It turns grainy, then separates into butter and buttermilk. Stop as soon as the peak stands.
• Under-whipping for meringue. It spreads in the oven or weeps.

In recipes

"Beat until stiff but not dry" means stop when the peak stands but the whites still look moist and glossy. "Firm peaks" is a term some recipes use for a stage just before fully stiff.